1. Field of the Invention
The invention generally relates to continuous passive motion exercise equipment, and more specifically to a multiple axis exerciser used for moving the foot.
2. Description of the Related Art
Continuous passive motion of joints for therapeutic reasons is an area undergoing growth. By passively moving the desired joint when the patient is not capable, joint, ligament and muscle degradation is reduced while the patient is recovering sufficiently to allow him to perform the exercises on his own volition. Continuous passive motion generally is a gentle cyclic motion of the particular joint along its natural axes. Various devices are well known for doing this, many being related to the hip, knee and a single axis of the ankle. Other devices are available for shoulders, elbows and the fingers of the hand.
One complicating factor to development of devices for several joints such as the ankle, hip or shoulder is that these are joints that can move in a large number of axes. Unlike the elbow and the knee, which are effectively only single axis or pinned joints, the ankle, hip and shoulder can move in three independent axes, at least within certain movement ranges. This greatly complicates exerciser design if adjustments for the various axes are to be determined. Typically this has been resolved by using separate machines for the separate motions or axes, thus not allowing concurrent motions of the various axes.
One area where multiple axis continuous passive motion is desirable is in the treatment of hind or club feet in infants. Many infants are born with their feet in a hind or curled position and having relatively limited movement. One prior technique for helping to correct this situation required a therapist on a periodic basis to use large amounts of force to attempt to stretch the various ligaments, tendons and other elements in the ankle which were causing the condition. This was quite painful to the child because of the great forces used and great stresses developed. Additionally, access to a trained therapist was required on a frequent basis, thus increasing expenses and being very inconvenient.
A second alternative was a surgical technique. The necessary elements were severed and lengthened so that various portions could be reattached in a more natural location and proper movement of the foot could be obtained. This was quite complicated and often resulted in the foot being immobile for long periods of time while any healing or mending took place. Additionally, it was a surgical procedure on an infant with all the resultant problems and concerns. Quite often the combination of the two techniques was utilized, further increasing costs and difficulties.